Electric machines, for example motors and generators, are used in numerous areas of technology. The electric machines comprise a stator and a rotor. The rotor and the stator are surrounded by a housing that is used to protect the electric machine.
Heat can be generated during the operation of the electric machine and said heat must then be dissipated. It is possible to provide a cooling arrangement on the housing. By way of example, electric machines having a cooled housing are known from DE 102004013133 A1 and DE 102010010395 A1.
In the case of fluid-cooled electric machines, the housings are embodied predominately as one part with a cooling channel. Alternatively, the housings for fluid-cooled electric machines can be embodied in two parts. The inner part of the housing can be embodied with a relatively thick wall in order to be able to support the cooling geometry.
It is possible to increase the external diameter of the housing by virtue of integrating the cooling arrangement in the housing, as a consequence of which expensive installation space is involved, for example in vehicles. Moreover, housings can comprise costly interfaces for the electric machine, for example to a stator iron core. Said interfaces can be associated with high labor costs during the production of the electric machine. Moreover, strong forces can act on the electric machine and/or on the housing in the region of these interfaces.